xref: /linux/drivers/iio/inkern.c (revision e3966940559d52aa1800a008dcfeec218dd31f88)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core in kernel channel mapping
3  *
4  * Copyright (c) 2011 Jonathan Cameron
5  */
6 #include <linux/cleanup.h>
7 #include <linux/err.h>
8 #include <linux/export.h>
9 #include <linux/minmax.h>
10 #include <linux/mm.h>
11 #include <linux/mutex.h>
12 #include <linux/property.h>
13 #include <linux/slab.h>
14 #include <linux/units.h>
15 
16 #include <linux/iio/iio.h>
17 #include <linux/iio/iio-opaque.h>
18 #include "iio_core.h"
19 #include <linux/iio/machine.h>
20 #include <linux/iio/driver.h>
21 #include <linux/iio/consumer.h>
22 
23 struct iio_map_internal {
24 	struct iio_dev *indio_dev;
25 	const struct iio_map *map;
26 	struct list_head l;
27 };
28 
29 static LIST_HEAD(iio_map_list);
30 static DEFINE_MUTEX(iio_map_list_lock);
31 
32 static int iio_map_array_unregister_locked(struct iio_dev *indio_dev)
33 {
34 	int ret = -ENODEV;
35 	struct iio_map_internal *mapi, *next;
36 
37 	list_for_each_entry_safe(mapi, next, &iio_map_list, l) {
38 		if (indio_dev == mapi->indio_dev) {
39 			list_del(&mapi->l);
40 			kfree(mapi);
41 			ret = 0;
42 		}
43 	}
44 	return ret;
45 }
46 
47 int iio_map_array_register(struct iio_dev *indio_dev, const struct iio_map *maps)
48 {
49 	struct iio_map_internal *mapi;
50 	int i = 0;
51 	int ret;
52 
53 	if (!maps)
54 		return 0;
55 
56 	guard(mutex)(&iio_map_list_lock);
57 	while (maps[i].consumer_dev_name) {
58 		mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
59 		if (!mapi) {
60 			ret = -ENOMEM;
61 			goto error_ret;
62 		}
63 		mapi->map = &maps[i];
64 		mapi->indio_dev = indio_dev;
65 		list_add_tail(&mapi->l, &iio_map_list);
66 		i++;
67 	}
68 
69 	return 0;
70 error_ret:
71 	iio_map_array_unregister_locked(indio_dev);
72 	return ret;
73 }
74 EXPORT_SYMBOL_GPL(iio_map_array_register);
75 
76 /*
77  * Remove all map entries associated with the given iio device
78  */
79 int iio_map_array_unregister(struct iio_dev *indio_dev)
80 {
81 	guard(mutex)(&iio_map_list_lock);
82 	return iio_map_array_unregister_locked(indio_dev);
83 }
84 EXPORT_SYMBOL_GPL(iio_map_array_unregister);
85 
86 static void iio_map_array_unregister_cb(void *indio_dev)
87 {
88 	iio_map_array_unregister(indio_dev);
89 }
90 
91 int devm_iio_map_array_register(struct device *dev, struct iio_dev *indio_dev,
92 				const struct iio_map *maps)
93 {
94 	int ret;
95 
96 	ret = iio_map_array_register(indio_dev, maps);
97 	if (ret)
98 		return ret;
99 
100 	return devm_add_action_or_reset(dev, iio_map_array_unregister_cb, indio_dev);
101 }
102 EXPORT_SYMBOL_GPL(devm_iio_map_array_register);
103 
104 static const struct iio_chan_spec
105 *iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
106 {
107 	int i;
108 	const struct iio_chan_spec *chan = NULL;
109 
110 	for (i = 0; i < indio_dev->num_channels; i++)
111 		if (indio_dev->channels[i].datasheet_name &&
112 		    strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
113 			chan = &indio_dev->channels[i];
114 			break;
115 		}
116 	return chan;
117 }
118 
119 /**
120  * __fwnode_iio_simple_xlate - translate iiospec to the IIO channel index
121  * @indio_dev:	pointer to the iio_dev structure
122  * @iiospec:	IIO specifier as found in the device tree
123  *
124  * This is simple translation function, suitable for the most 1:1 mapped
125  * channels in IIO chips. This function performs only one sanity check:
126  * whether IIO index is less than num_channels (that is specified in the
127  * iio_dev).
128  */
129 static int __fwnode_iio_simple_xlate(struct iio_dev *indio_dev,
130 				     const struct fwnode_reference_args *iiospec)
131 {
132 	if (!iiospec->nargs)
133 		return 0;
134 
135 	if (iiospec->args[0] >= indio_dev->num_channels) {
136 		dev_err(&indio_dev->dev, "invalid channel index %llu\n",
137 			iiospec->args[0]);
138 		return -EINVAL;
139 	}
140 
141 	return iiospec->args[0];
142 }
143 
144 static int __fwnode_iio_channel_get(struct iio_channel *channel,
145 				    struct fwnode_handle *fwnode, int index)
146 {
147 	struct fwnode_reference_args iiospec;
148 	struct device *idev;
149 	struct iio_dev *indio_dev;
150 	int err;
151 
152 	err = fwnode_property_get_reference_args(fwnode, "io-channels",
153 						 "#io-channel-cells", 0,
154 						 index, &iiospec);
155 	if (err)
156 		return err;
157 
158 	idev = bus_find_device_by_fwnode(&iio_bus_type, iiospec.fwnode);
159 	if (!idev) {
160 		fwnode_handle_put(iiospec.fwnode);
161 		return -EPROBE_DEFER;
162 	}
163 
164 	indio_dev = dev_to_iio_dev(idev);
165 	channel->indio_dev = indio_dev;
166 	if (indio_dev->info->fwnode_xlate)
167 		index = indio_dev->info->fwnode_xlate(indio_dev, &iiospec);
168 	else
169 		index = __fwnode_iio_simple_xlate(indio_dev, &iiospec);
170 	fwnode_handle_put(iiospec.fwnode);
171 	if (index < 0)
172 		goto err_put;
173 	channel->channel = &indio_dev->channels[index];
174 
175 	return 0;
176 
177 err_put:
178 	iio_device_put(indio_dev);
179 	return index;
180 }
181 
182 static struct iio_channel *fwnode_iio_channel_get(struct fwnode_handle *fwnode,
183 						  int index)
184 {
185 	int err;
186 
187 	if (index < 0)
188 		return ERR_PTR(-EINVAL);
189 
190 	struct iio_channel *channel __free(kfree) =
191 		kzalloc(sizeof(*channel), GFP_KERNEL);
192 	if (!channel)
193 		return ERR_PTR(-ENOMEM);
194 
195 	err = __fwnode_iio_channel_get(channel, fwnode, index);
196 	if (err)
197 		return ERR_PTR(err);
198 
199 	return_ptr(channel);
200 }
201 
202 static struct iio_channel *
203 __fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode, const char *name)
204 {
205 	struct iio_channel *chan;
206 	int index = 0;
207 
208 	/*
209 	 * For named iio channels, first look up the name in the
210 	 * "io-channel-names" property.  If it cannot be found, the
211 	 * index will be an error code, and fwnode_iio_channel_get()
212 	 * will fail.
213 	 */
214 	if (name)
215 		index = fwnode_property_match_string(fwnode, "io-channel-names",
216 						     name);
217 
218 	chan = fwnode_iio_channel_get(fwnode, index);
219 	if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
220 		return chan;
221 	if (name) {
222 		if (index >= 0) {
223 			pr_err("ERROR: could not get IIO channel %pfw:%s(%i)\n",
224 			       fwnode, name, index);
225 			/*
226 			 * In this case, we found 'name' in 'io-channel-names'
227 			 * but somehow we still fail so that we should not proceed
228 			 * with any other lookup. Hence, explicitly return -EINVAL
229 			 * (maybe not the better error code) so that the caller
230 			 * won't do a system lookup.
231 			 */
232 			return ERR_PTR(-EINVAL);
233 		}
234 		/*
235 		 * If index < 0, then fwnode_property_get_reference_args() fails
236 		 * with -EINVAL or -ENOENT (ACPI case) which is expected. We
237 		 * should not proceed if we get any other error.
238 		 */
239 		if (PTR_ERR(chan) != -EINVAL && PTR_ERR(chan) != -ENOENT)
240 			return chan;
241 	} else if (PTR_ERR(chan) != -ENOENT) {
242 		/*
243 		 * if !name, then we should only proceed the lookup if
244 		 * fwnode_property_get_reference_args() returns -ENOENT.
245 		 */
246 		return chan;
247 	}
248 
249 	/* so we continue the lookup */
250 	return ERR_PTR(-ENODEV);
251 }
252 
253 struct iio_channel *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode,
254 						   const char *name)
255 {
256 	struct fwnode_handle *parent;
257 	struct iio_channel *chan;
258 
259 	/* Walk up the tree of devices looking for a matching iio channel */
260 	chan = __fwnode_iio_channel_get_by_name(fwnode, name);
261 	if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV)
262 		return chan;
263 
264 	/*
265 	 * No matching IIO channel found on this node.
266 	 * If the parent node has a "io-channel-ranges" property,
267 	 * then we can try one of its channels.
268 	 */
269 	fwnode_for_each_parent_node(fwnode, parent) {
270 		if (!fwnode_property_present(parent, "io-channel-ranges")) {
271 			fwnode_handle_put(parent);
272 			return ERR_PTR(-ENODEV);
273 		}
274 
275 		chan = __fwnode_iio_channel_get_by_name(parent, name);
276 		if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV) {
277 			fwnode_handle_put(parent);
278  			return chan;
279 		}
280 	}
281 
282 	return ERR_PTR(-ENODEV);
283 }
284 EXPORT_SYMBOL_GPL(fwnode_iio_channel_get_by_name);
285 
286 static struct iio_channel *fwnode_iio_channel_get_all(struct device *dev)
287 {
288 	struct fwnode_handle *fwnode = dev_fwnode(dev);
289 	int i, mapind, nummaps = 0;
290 	int ret;
291 
292 	do {
293 		ret = fwnode_property_get_reference_args(fwnode, "io-channels",
294 							 "#io-channel-cells", 0,
295 							 nummaps, NULL);
296 		if (ret < 0)
297 			break;
298 	} while (++nummaps);
299 
300 	if (nummaps == 0)
301 		return ERR_PTR(-ENODEV);
302 
303 	/* NULL terminated array to save passing size */
304 	struct iio_channel *chans __free(kfree) =
305 		kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
306 	if (!chans)
307 		return ERR_PTR(-ENOMEM);
308 
309 	/* Search for FW matches */
310 	for (mapind = 0; mapind < nummaps; mapind++) {
311 		ret = __fwnode_iio_channel_get(&chans[mapind], fwnode, mapind);
312 		if (ret)
313 			goto error_free_chans;
314 	}
315 	return_ptr(chans);
316 
317 error_free_chans:
318 	for (i = 0; i < mapind; i++)
319 		iio_device_put(chans[i].indio_dev);
320 	return ERR_PTR(ret);
321 }
322 
323 static struct iio_channel *iio_channel_get_sys(const char *name,
324 					       const char *channel_name)
325 {
326 	struct iio_map_internal *c_i = NULL, *c = NULL;
327 	int err;
328 
329 	if (!(name || channel_name))
330 		return ERR_PTR(-ENODEV);
331 
332 	/* first find matching entry the channel map */
333 	scoped_guard(mutex, &iio_map_list_lock) {
334 		list_for_each_entry(c_i, &iio_map_list, l) {
335 			if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
336 			    (channel_name &&
337 			     strcmp(channel_name, c_i->map->consumer_channel) != 0))
338 				continue;
339 			c = c_i;
340 			iio_device_get(c->indio_dev);
341 			break;
342 		}
343 	}
344 	if (!c)
345 		return ERR_PTR(-ENODEV);
346 
347 	struct iio_channel *channel __free(kfree) =
348 		kzalloc(sizeof(*channel), GFP_KERNEL);
349 	if (!channel) {
350 		err = -ENOMEM;
351 		goto error_no_mem;
352 	}
353 
354 	channel->indio_dev = c->indio_dev;
355 
356 	if (c->map->adc_channel_label) {
357 		channel->channel =
358 			iio_chan_spec_from_name(channel->indio_dev,
359 						c->map->adc_channel_label);
360 
361 		if (!channel->channel) {
362 			err = -EINVAL;
363 			goto error_no_mem;
364 		}
365 	}
366 
367 	return_ptr(channel);
368 
369 error_no_mem:
370 	iio_device_put(c->indio_dev);
371 	return ERR_PTR(err);
372 }
373 
374 struct iio_channel *iio_channel_get(struct device *dev,
375 				    const char *channel_name)
376 {
377 	const char *name = dev ? dev_name(dev) : NULL;
378 	struct iio_channel *channel;
379 
380 	if (dev) {
381 		channel = fwnode_iio_channel_get_by_name(dev_fwnode(dev),
382 							 channel_name);
383 		if (!IS_ERR(channel) || PTR_ERR(channel) != -ENODEV)
384 			return channel;
385 	}
386 
387 	return iio_channel_get_sys(name, channel_name);
388 }
389 EXPORT_SYMBOL_GPL(iio_channel_get);
390 
391 void iio_channel_release(struct iio_channel *channel)
392 {
393 	if (!channel)
394 		return;
395 	iio_device_put(channel->indio_dev);
396 	kfree(channel);
397 }
398 EXPORT_SYMBOL_GPL(iio_channel_release);
399 
400 static void devm_iio_channel_free(void *iio_channel)
401 {
402 	iio_channel_release(iio_channel);
403 }
404 
405 struct iio_channel *devm_iio_channel_get(struct device *dev,
406 					 const char *channel_name)
407 {
408 	struct iio_channel *channel;
409 	int ret;
410 
411 	channel = iio_channel_get(dev, channel_name);
412 	if (IS_ERR(channel))
413 		return channel;
414 
415 	ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
416 	if (ret)
417 		return ERR_PTR(ret);
418 
419 	return channel;
420 }
421 EXPORT_SYMBOL_GPL(devm_iio_channel_get);
422 
423 struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
424 							struct fwnode_handle *fwnode,
425 							const char *channel_name)
426 {
427 	struct iio_channel *channel;
428 	int ret;
429 
430 	channel = fwnode_iio_channel_get_by_name(fwnode, channel_name);
431 	if (IS_ERR(channel))
432 		return channel;
433 
434 	ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
435 	if (ret)
436 		return ERR_PTR(ret);
437 
438 	return channel;
439 }
440 EXPORT_SYMBOL_GPL(devm_fwnode_iio_channel_get_by_name);
441 
442 struct iio_channel *iio_channel_get_all(struct device *dev)
443 {
444 	const char *name;
445 	struct iio_map_internal *c = NULL;
446 	struct iio_channel *fw_chans;
447 	int nummaps = 0;
448 	int mapind = 0;
449 	int i, ret;
450 
451 	if (!dev)
452 		return ERR_PTR(-EINVAL);
453 
454 	fw_chans = fwnode_iio_channel_get_all(dev);
455 	/*
456 	 * We only want to carry on if the error is -ENODEV.  Anything else
457 	 * should be reported up the stack.
458 	 */
459 	if (!IS_ERR(fw_chans) || PTR_ERR(fw_chans) != -ENODEV)
460 		return fw_chans;
461 
462 	name = dev_name(dev);
463 
464 	guard(mutex)(&iio_map_list_lock);
465 	/* first count the matching maps */
466 	list_for_each_entry(c, &iio_map_list, l)
467 		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
468 			continue;
469 		else
470 			nummaps++;
471 
472 	if (nummaps == 0)
473 		return ERR_PTR(-ENODEV);
474 
475 	/* NULL terminated array to save passing size */
476 	struct iio_channel *chans __free(kfree) =
477 		kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
478 	if (!chans)
479 		return ERR_PTR(-ENOMEM);
480 
481 	/* for each map fill in the chans element */
482 	list_for_each_entry(c, &iio_map_list, l) {
483 		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
484 			continue;
485 		chans[mapind].indio_dev = c->indio_dev;
486 		chans[mapind].data = c->map->consumer_data;
487 		chans[mapind].channel =
488 			iio_chan_spec_from_name(chans[mapind].indio_dev,
489 						c->map->adc_channel_label);
490 		if (!chans[mapind].channel) {
491 			ret = -EINVAL;
492 			goto error_free_chans;
493 		}
494 		iio_device_get(chans[mapind].indio_dev);
495 		mapind++;
496 	}
497 	if (mapind == 0) {
498 		ret = -ENODEV;
499 		goto error_free_chans;
500 	}
501 
502 	return_ptr(chans);
503 
504 error_free_chans:
505 	for (i = 0; i < mapind; i++)
506 		iio_device_put(chans[i].indio_dev);
507 	return ERR_PTR(ret);
508 }
509 EXPORT_SYMBOL_GPL(iio_channel_get_all);
510 
511 void iio_channel_release_all(struct iio_channel *channels)
512 {
513 	struct iio_channel *chan = &channels[0];
514 
515 	while (chan->indio_dev) {
516 		iio_device_put(chan->indio_dev);
517 		chan++;
518 	}
519 	kfree(channels);
520 }
521 EXPORT_SYMBOL_GPL(iio_channel_release_all);
522 
523 static void devm_iio_channel_free_all(void *iio_channels)
524 {
525 	iio_channel_release_all(iio_channels);
526 }
527 
528 struct iio_channel *devm_iio_channel_get_all(struct device *dev)
529 {
530 	struct iio_channel *channels;
531 	int ret;
532 
533 	channels = iio_channel_get_all(dev);
534 	if (IS_ERR(channels))
535 		return channels;
536 
537 	ret = devm_add_action_or_reset(dev, devm_iio_channel_free_all,
538 				       channels);
539 	if (ret)
540 		return ERR_PTR(ret);
541 
542 	return channels;
543 }
544 EXPORT_SYMBOL_GPL(devm_iio_channel_get_all);
545 
546 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
547 			    enum iio_chan_info_enum info)
548 {
549 	const struct iio_info *iio_info = chan->indio_dev->info;
550 	int unused;
551 	int vals[INDIO_MAX_RAW_ELEMENTS];
552 	int ret;
553 	int val_len = 2;
554 
555 	if (!val2)
556 		val2 = &unused;
557 
558 	if (!iio_channel_has_info(chan->channel, info))
559 		return -EINVAL;
560 
561 	if (iio_info->read_raw_multi) {
562 		ret = iio_info->read_raw_multi(chan->indio_dev,
563 					       chan->channel,
564 					       INDIO_MAX_RAW_ELEMENTS,
565 					       vals, &val_len, info);
566 		*val = vals[0];
567 		*val2 = vals[1];
568 	} else if (iio_info->read_raw) {
569 		ret = iio_info->read_raw(chan->indio_dev,
570 					 chan->channel, val, val2, info);
571 	} else {
572 		return -EINVAL;
573 	}
574 
575 	return ret;
576 }
577 
578 int iio_read_channel_raw(struct iio_channel *chan, int *val)
579 {
580 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
581 
582 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
583 	if (!chan->indio_dev->info)
584 		return -ENODEV;
585 
586 	return iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
587 }
588 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
589 
590 int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
591 {
592 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
593 
594 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
595 	if (!chan->indio_dev->info)
596 		return -ENODEV;
597 
598 	return iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
599 }
600 EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
601 
602 int iio_multiply_value(int *result, s64 multiplier,
603 		       unsigned int type, int val, int val2)
604 {
605 	s64 denominator;
606 
607 	switch (type) {
608 	case IIO_VAL_INT:
609 		*result = multiplier * val;
610 		return IIO_VAL_INT;
611 	case IIO_VAL_INT_PLUS_MICRO:
612 	case IIO_VAL_INT_PLUS_NANO:
613 		switch (type) {
614 		case IIO_VAL_INT_PLUS_MICRO:
615 			denominator = MICRO;
616 			break;
617 		case IIO_VAL_INT_PLUS_NANO:
618 			denominator = NANO;
619 			break;
620 		}
621 		*result = multiplier * abs(val);
622 		*result += div_s64(multiplier * abs(val2), denominator);
623 		if (val < 0 || val2 < 0)
624 			*result *= -1;
625 		return IIO_VAL_INT;
626 	case IIO_VAL_FRACTIONAL:
627 		*result = div_s64(multiplier * val, val2);
628 		return IIO_VAL_INT;
629 	case IIO_VAL_FRACTIONAL_LOG2:
630 		*result = (multiplier * val) >> val2;
631 		return IIO_VAL_INT;
632 	default:
633 		return -EINVAL;
634 	}
635 }
636 EXPORT_SYMBOL_NS_GPL(iio_multiply_value, "IIO_UNIT_TEST");
637 
638 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
639 						 int raw, int *processed,
640 						 unsigned int scale)
641 {
642 	int scale_type, scale_val, scale_val2;
643 	int offset_type, offset_val, offset_val2;
644 	s64 raw64 = raw;
645 	int ret;
646 
647 	offset_type = iio_channel_read(chan, &offset_val, &offset_val2,
648 				       IIO_CHAN_INFO_OFFSET);
649 	if (offset_type >= 0) {
650 		switch (offset_type) {
651 		case IIO_VAL_INT:
652 			break;
653 		case IIO_VAL_INT_PLUS_MICRO:
654 		case IIO_VAL_INT_PLUS_NANO:
655 			/*
656 			 * Both IIO_VAL_INT_PLUS_MICRO and IIO_VAL_INT_PLUS_NANO
657 			 * implicitely truncate the offset to it's integer form.
658 			 */
659 			break;
660 		case IIO_VAL_FRACTIONAL:
661 			offset_val /= offset_val2;
662 			break;
663 		case IIO_VAL_FRACTIONAL_LOG2:
664 			offset_val >>= offset_val2;
665 			break;
666 		default:
667 			return -EINVAL;
668 		}
669 
670 		raw64 += offset_val;
671 	}
672 
673 	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
674 				      IIO_CHAN_INFO_SCALE);
675 	if (scale_type < 0) {
676 		/*
677 		 * If no channel scaling is available apply consumer scale to
678 		 * raw value and return.
679 		 */
680 		*processed = raw64 * scale;
681 		return 0;
682 	}
683 
684 	ret = iio_multiply_value(processed, raw64 * scale,
685 				 scale_type, scale_val, scale_val2);
686 	if (ret < 0)
687 		return ret;
688 
689 	return 0;
690 }
691 
692 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
693 				 int *processed, unsigned int scale)
694 {
695 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
696 
697 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
698 	if (!chan->indio_dev->info)
699 		return -ENODEV;
700 
701 	return iio_convert_raw_to_processed_unlocked(chan, raw, processed,
702 						     scale);
703 }
704 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
705 
706 int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
707 			       enum iio_chan_info_enum attribute)
708 {
709 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
710 
711 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
712 	if (!chan->indio_dev->info)
713 		return -ENODEV;
714 
715 	return iio_channel_read(chan, val, val2, attribute);
716 }
717 EXPORT_SYMBOL_GPL(iio_read_channel_attribute);
718 
719 int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
720 {
721 	return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET);
722 }
723 EXPORT_SYMBOL_GPL(iio_read_channel_offset);
724 
725 int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
726 				     unsigned int scale)
727 {
728 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
729 	int ret, pval, pval2;
730 
731 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
732 	if (!chan->indio_dev->info)
733 		return -ENODEV;
734 
735 	if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
736 		ret = iio_channel_read(chan, &pval, &pval2,
737 				       IIO_CHAN_INFO_PROCESSED);
738 		if (ret < 0)
739 			return ret;
740 
741 		return iio_multiply_value(val, scale, ret, pval, pval2);
742 	} else {
743 		ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
744 		if (ret < 0)
745 			return ret;
746 
747 		return iio_convert_raw_to_processed_unlocked(chan, *val, val,
748 							     scale);
749 	}
750 }
751 EXPORT_SYMBOL_GPL(iio_read_channel_processed_scale);
752 
753 int iio_read_channel_processed(struct iio_channel *chan, int *val)
754 {
755 	/* This is just a special case with scale factor 1 */
756 	return iio_read_channel_processed_scale(chan, val, 1);
757 }
758 EXPORT_SYMBOL_GPL(iio_read_channel_processed);
759 
760 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
761 {
762 	return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE);
763 }
764 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
765 
766 static int iio_channel_read_avail(struct iio_channel *chan,
767 				  const int **vals, int *type, int *length,
768 				  enum iio_chan_info_enum info)
769 {
770 	const struct iio_info *iio_info = chan->indio_dev->info;
771 
772 	if (!iio_channel_has_available(chan->channel, info))
773 		return -EINVAL;
774 
775 	if (iio_info->read_avail)
776 		return iio_info->read_avail(chan->indio_dev, chan->channel,
777 					    vals, type, length, info);
778 	return -EINVAL;
779 }
780 
781 int iio_read_avail_channel_attribute(struct iio_channel *chan,
782 				     const int **vals, int *type, int *length,
783 				     enum iio_chan_info_enum attribute)
784 {
785 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
786 
787 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
788 	if (!chan->indio_dev->info)
789 		return -ENODEV;
790 
791 	return iio_channel_read_avail(chan, vals, type, length, attribute);
792 }
793 EXPORT_SYMBOL_GPL(iio_read_avail_channel_attribute);
794 
795 int iio_read_avail_channel_raw(struct iio_channel *chan,
796 			       const int **vals, int *length)
797 {
798 	int ret;
799 	int type;
800 
801 	ret = iio_read_avail_channel_attribute(chan, vals, &type, length,
802 					       IIO_CHAN_INFO_RAW);
803 
804 	if (ret >= 0 && type != IIO_VAL_INT)
805 		/* raw values are assumed to be IIO_VAL_INT */
806 		ret = -EINVAL;
807 
808 	return ret;
809 }
810 EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw);
811 
812 static int iio_channel_read_max(struct iio_channel *chan,
813 				int *val, int *val2, int *type,
814 				enum iio_chan_info_enum info)
815 {
816 	const int *vals;
817 	int length;
818 	int ret;
819 
820 	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
821 	if (ret < 0)
822 		return ret;
823 
824 	switch (ret) {
825 	case IIO_AVAIL_RANGE:
826 		switch (*type) {
827 		case IIO_VAL_INT:
828 			*val = vals[2];
829 			break;
830 		default:
831 			*val = vals[4];
832 			if (val2)
833 				*val2 = vals[5];
834 		}
835 		return 0;
836 
837 	case IIO_AVAIL_LIST:
838 		if (length <= 0)
839 			return -EINVAL;
840 		switch (*type) {
841 		case IIO_VAL_INT:
842 			*val = max_array(vals, length);
843 			break;
844 		default:
845 			/* TODO: learn about max for other iio values */
846 			return -EINVAL;
847 		}
848 		return 0;
849 
850 	default:
851 		return -EINVAL;
852 	}
853 }
854 
855 int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
856 {
857 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
858 	int type;
859 
860 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
861 	if (!chan->indio_dev->info)
862 		return -ENODEV;
863 
864 	return iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
865 }
866 EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
867 
868 static int iio_channel_read_min(struct iio_channel *chan,
869 				int *val, int *val2, int *type,
870 				enum iio_chan_info_enum info)
871 {
872 	const int *vals;
873 	int length;
874 	int ret;
875 
876 	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
877 	if (ret < 0)
878 		return ret;
879 
880 	switch (ret) {
881 	case IIO_AVAIL_RANGE:
882 		switch (*type) {
883 		case IIO_VAL_INT:
884 			*val = vals[0];
885 			break;
886 		default:
887 			*val = vals[0];
888 			if (val2)
889 				*val2 = vals[1];
890 		}
891 		return 0;
892 
893 	case IIO_AVAIL_LIST:
894 		if (length <= 0)
895 			return -EINVAL;
896 		switch (*type) {
897 		case IIO_VAL_INT:
898 			*val = min_array(vals, length);
899 			break;
900 		default:
901 			/* TODO: learn about min for other iio values */
902 			return -EINVAL;
903 		}
904 		return 0;
905 
906 	default:
907 		return -EINVAL;
908 	}
909 }
910 
911 int iio_read_min_channel_raw(struct iio_channel *chan, int *val)
912 {
913 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
914 	int type;
915 
916 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
917 	if (!chan->indio_dev->info)
918 		return -ENODEV;
919 
920 	return iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
921 }
922 EXPORT_SYMBOL_GPL(iio_read_min_channel_raw);
923 
924 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
925 {
926 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
927 
928 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
929 	if (!chan->indio_dev->info)
930 		return -ENODEV;
931 
932 	*type = chan->channel->type;
933 
934 	return 0;
935 }
936 EXPORT_SYMBOL_GPL(iio_get_channel_type);
937 
938 static int iio_channel_write(struct iio_channel *chan, int val, int val2,
939 			     enum iio_chan_info_enum info)
940 {
941 	const struct iio_info *iio_info = chan->indio_dev->info;
942 
943 	if (iio_info->write_raw)
944 		return iio_info->write_raw(chan->indio_dev,
945 					   chan->channel, val, val2, info);
946 	return -EINVAL;
947 }
948 
949 int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
950 				enum iio_chan_info_enum attribute)
951 {
952 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
953 
954 	guard(mutex)(&iio_dev_opaque->info_exist_lock);
955 	if (!chan->indio_dev->info)
956 		return -ENODEV;
957 
958 	return iio_channel_write(chan, val, val2, attribute);
959 }
960 EXPORT_SYMBOL_GPL(iio_write_channel_attribute);
961 
962 int iio_write_channel_raw(struct iio_channel *chan, int val)
963 {
964 	return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW);
965 }
966 EXPORT_SYMBOL_GPL(iio_write_channel_raw);
967 
968 unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
969 {
970 	const struct iio_chan_spec_ext_info *ext_info;
971 	unsigned int i = 0;
972 
973 	if (!chan->channel->ext_info)
974 		return i;
975 
976 	for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
977 		++i;
978 
979 	return i;
980 }
981 EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
982 
983 static const struct iio_chan_spec_ext_info *
984 iio_lookup_ext_info(const struct iio_channel *chan, const char *attr)
985 {
986 	const struct iio_chan_spec_ext_info *ext_info;
987 
988 	if (!chan->channel->ext_info)
989 		return NULL;
990 
991 	for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
992 		if (!strcmp(attr, ext_info->name))
993 			return ext_info;
994 	}
995 
996 	return NULL;
997 }
998 
999 ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
1000 				  const char *attr, char *buf)
1001 {
1002 	const struct iio_chan_spec_ext_info *ext_info;
1003 
1004 	if (!buf || offset_in_page(buf)) {
1005 		pr_err("iio: invalid ext_info read buffer\n");
1006 		return -EINVAL;
1007 	}
1008 
1009 	ext_info = iio_lookup_ext_info(chan, attr);
1010 	if (!ext_info)
1011 		return -EINVAL;
1012 
1013 	return ext_info->read(chan->indio_dev, ext_info->private,
1014 			      chan->channel, buf);
1015 }
1016 EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
1017 
1018 ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
1019 				   const char *buf, size_t len)
1020 {
1021 	const struct iio_chan_spec_ext_info *ext_info;
1022 
1023 	ext_info = iio_lookup_ext_info(chan, attr);
1024 	if (!ext_info)
1025 		return -EINVAL;
1026 
1027 	return ext_info->write(chan->indio_dev, ext_info->private,
1028 			       chan->channel, buf, len);
1029 }
1030 EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
1031 
1032 ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf)
1033 {
1034 	if (!buf || offset_in_page(buf)) {
1035 		pr_err("iio: invalid label read buffer\n");
1036 		return -EINVAL;
1037 	}
1038 
1039 	return do_iio_read_channel_label(chan->indio_dev, chan->channel, buf);
1040 }
1041 EXPORT_SYMBOL_GPL(iio_read_channel_label);
1042